I use a helly hansen on the bike under my winter jacket as necessary. I also have various mountaineering type base layers (eg Lowe Alpine Dryflo, Lifa, Berghaus X-static, CoolMax etc) they are all either polyester or polypropylene and the major differences between them is often weight (and warmth), how much they wiff after a day's wear, and if they have a zip on the neck. oh, and how soft they feel. Cheaper stuff might wick slightly less well, be less well designed, and smell a bit more! Whether that is important is debatable and you can judge most of them (except the stink!) when you try one on.